Gov. Arnold Schwarzenegger had arthroscopic surgery to repair a knee he injured about two weeks ago while working out, the second time he's been under a doctor's knife in about 20 months, his office disclosed Sunday. Schwarzenegger spokesman Matt David said the governor was in good spirits after the Saturday evening operation and attended church on Sunday, walking without assistance. The former bodybuilding champion and actor had pulled out of an environmental forum in Lake Tahoe on Saturday to have the right knee examined. Schwarzenegger was under anesthesia for about 45 minutes, during which time the powers of office were transferred to Lt. Gov. John Garamendi. He was expected to return to Sacramento on Monday.